Database
REAL AND COMPLEX NUMBERS
Order sets
Infinity and the extended real number system (cont.)
xltmul1
Next ⟩
xltmul2
Metamath Proof Explorer
Ascii
Unicode
Theorem
xltmul1
Description:
Extended real version of
ltmul1
.
(Contributed by
Mario Carneiro
, 20-Aug-2015)
Ref
Expression
Assertion
xltmul1
⊢
A
∈
ℝ
*
∧
B
∈
ℝ
*
∧
C
∈
ℝ
+
→
A
<
B
↔
A
⋅
𝑒
C
<
B
⋅
𝑒
C
Proof
Step
Hyp
Ref
Expression
1
xlemul1
⊢
B
∈
ℝ
*
∧
A
∈
ℝ
*
∧
C
∈
ℝ
+
→
B
≤
A
↔
B
⋅
𝑒
C
≤
A
⋅
𝑒
C
2
1
3com12
⊢
A
∈
ℝ
*
∧
B
∈
ℝ
*
∧
C
∈
ℝ
+
→
B
≤
A
↔
B
⋅
𝑒
C
≤
A
⋅
𝑒
C
3
2
notbid
⊢
A
∈
ℝ
*
∧
B
∈
ℝ
*
∧
C
∈
ℝ
+
→
¬
B
≤
A
↔
¬
B
⋅
𝑒
C
≤
A
⋅
𝑒
C
4
xrltnle
⊢
A
∈
ℝ
*
∧
B
∈
ℝ
*
→
A
<
B
↔
¬
B
≤
A
5
4
3adant3
⊢
A
∈
ℝ
*
∧
B
∈
ℝ
*
∧
C
∈
ℝ
+
→
A
<
B
↔
¬
B
≤
A
6
simp1
⊢
A
∈
ℝ
*
∧
B
∈
ℝ
*
∧
C
∈
ℝ
+
→
A
∈
ℝ
*
7
rpxr
⊢
C
∈
ℝ
+
→
C
∈
ℝ
*
8
7
3ad2ant3
⊢
A
∈
ℝ
*
∧
B
∈
ℝ
*
∧
C
∈
ℝ
+
→
C
∈
ℝ
*
9
xmulcl
⊢
A
∈
ℝ
*
∧
C
∈
ℝ
*
→
A
⋅
𝑒
C
∈
ℝ
*
10
6
8
9
syl2anc
⊢
A
∈
ℝ
*
∧
B
∈
ℝ
*
∧
C
∈
ℝ
+
→
A
⋅
𝑒
C
∈
ℝ
*
11
simp2
⊢
A
∈
ℝ
*
∧
B
∈
ℝ
*
∧
C
∈
ℝ
+
→
B
∈
ℝ
*
12
xmulcl
⊢
B
∈
ℝ
*
∧
C
∈
ℝ
*
→
B
⋅
𝑒
C
∈
ℝ
*
13
11
8
12
syl2anc
⊢
A
∈
ℝ
*
∧
B
∈
ℝ
*
∧
C
∈
ℝ
+
→
B
⋅
𝑒
C
∈
ℝ
*
14
xrltnle
⊢
A
⋅
𝑒
C
∈
ℝ
*
∧
B
⋅
𝑒
C
∈
ℝ
*
→
A
⋅
𝑒
C
<
B
⋅
𝑒
C
↔
¬
B
⋅
𝑒
C
≤
A
⋅
𝑒
C
15
10
13
14
syl2anc
⊢
A
∈
ℝ
*
∧
B
∈
ℝ
*
∧
C
∈
ℝ
+
→
A
⋅
𝑒
C
<
B
⋅
𝑒
C
↔
¬
B
⋅
𝑒
C
≤
A
⋅
𝑒
C
16
3
5
15
3bitr4d
⊢
A
∈
ℝ
*
∧
B
∈
ℝ
*
∧
C
∈
ℝ
+
→
A
<
B
↔
A
⋅
𝑒
C
<
B
⋅
𝑒
C